


Promise?

by attackoneaj



Category: Day6 (Band), Shingeki no Kyojin | Attack on Titan
Genre: A lil fluff, Angst, Blood mentioned, Broken Promise, Crying, Day6 x AOT Au, Death, Fall of Wall Maria, Fall of Wall Rose, Hurt, Kisses, M/M, Non-Idol AU, Other, Screaming, alternative universe, battle of trost, but not really, lil comfort, mikasa is mentioned - Freeform
Language: English
Status: Completed
Published: 2021-02-11
Updated: 2021-02-11
Packaged: 2021-03-17 08:48:09
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 3,843
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29347650
Author URL: https://archiveofourown.org/users/attackoneaj/pseuds/attackoneaj
Summary: maybe if life was different for them, brian wouldn’t have broken his promise without meaning to.
Relationships: Kang Younghyun | Young K/Park Jaehyung | Jae
Comments: 2
Kudos: 7





	Promise?

**Author's Note:**

> p.s: this is what happens when ur a weeb & kpop fan
> 
> dont steal/repost my fics btw <3

_ year: 845 (the day wall maria falls) _

_ ages: 12 and 13 _

  
  


Jae has had a bad feeling  _ all  _ day but he couldn’t understand why he was feeling this way. Today was like any other day, he would wake up, get dressed, have breakfast with his family, and then go to his friend, Brian, house. Jae is currently on his way to the others house, walking slower than he usually does.

When he gets there, he sees Brian waiting outside for him, which he usually never does. “What took you so long?” the younger asks.

Jae frowns a little, “I have a bad feeling about today.”

Brian laughs a little at the taller male. “Everything will be fine, I’m sure of it! Now, let’s go down toward the entrance, I heard the scouts are coming back!”

The younger of the two have always loved the scouts and wanted to join one day. At their age, both of them were able to start training, though Brian wanted to wait a bit before doing so. Brian  _ begs _ the older male to join with him all the time, Jae would always say no. He agrees with the younger, that they are brave, but he also doesn’t want to be eaten by a titan.

“You’re moving slow again! Come on!” Brian yells, grabbing Jae’s hand and dragging him down to the crowd of people that are waiting for the scouts. A small gasp leaves the eldest lips.

They never stand close to the entrance, always by the end so they don’t have to hear the heartbroken families at the beginning. Jae knows for a fact that the second he sees someone cry, he would lose it too. He hates seeing people cry.

The two of them stand on boxes to see better. There’s a huge, bright smile on the younger's face as they wait for the scouts to pass by. This makes Jae smile a little.

“Come on Mikasa!” a boy yells out that is near the two boys. Jae watches as a boy and a girl not much younger than them, run past them. They kind of reminded Jae of him and Brian.

Sometime passes by and Brian is yelling out, “Look Jae, it’s Captain Levi!” Jae looks up to see the older man. His eyes move to the people behind them, their bodies either beaten up or they have limbs missing. This makes Jae frown and look away.

“Hey, whenever this is done, do you want to stop by my house? Mom wanted to ask you if you wanted to come over for lunch. We can also take the long way around to kill some time,” Jae says.

“I’d love to go over! Can we stop by my house to tell my dad first?” Brian asks.

“Yeah, of course.”

The two of them raced to the other males house when all the scouts had entered the gate, they were laughing on the way there. “You can come inside if you want,” Brian says as he opens the door. Once inside, the younger male says, “I’m going to be at Jae’s for lunch!”

His dad turns around, a smile on his face. “Alright, behave.”

“Will do!” Then the two boys leave the house, heading toward Jae’s.

Since they were taking the long way to the eldest house, it takes them close to the wall. They should be by it in about five minutes. The bad feeling Jae had felt earlier starts to come back, this time it’s a lot stronger. With each step they take, the stronger it gets.

“Are you okay? You look pale,” Brian says, looking at the other. There’s concern laced through his voice. They stop walking, Brian stands in front of Jae, away from the wall. They are about sixty meters away from the wall, from where they stopped at.

“That bad feeling… it’s gotten worse,” Jae mutters, holding his stomach. He feels like he’s about to be sick.

This is when Jae notices how  _ quiet  _ it is. Not too long after, lightning strikes on the other side of the wall. “What the hell was that?” Brian says, turning around, looking at the wall. They watch as people start to run past them, gathering by the wall.

The two boys slowly look up, gasps leaving their mouths as they see a titan hand on the way. “Is that?” Brian questions, his voice soft. Jae notices how the hand squeezes tighter

“Yeah… it is,” Jae replies. Everyone watches as a head starts to slowly rise and look down at them. The eldest of the two is listening carefully, his eyes widening more as he starts to hear movement from the other side of the wall. “We need to get away from the wall, we need to run,” Jae says, grabbing a hold of Brian’s hand.

“What, why?”

“He’s going to kick the wall, let’s  _ go, _ ” the elder says, running and dragging Brian with him.

Seconds pass by and there’s a loud noise, the two boys running watch as parts of the wall pass by them, smashing some of the buildings. People began to scream and cry. “H-He kicked the wall…” Brian whispers as they start to run faster. He tries to look back but Jae stops him.

“No, don’t. We need to make it back to your house and tell your dad what is going on. I’m sure he has heard the chaos by now though,” Jae says. They aren’t that far away from the younger males home.

Once there, they stop in front of the door, taking a breath. Jae throws the door open and yells, “Mr. Kang!”

Brian’s dad turns around, “Boys? What was all that ruckus outside?”

“A colossal titan has kicked the wall, titans are inside the wall,” Jae replies, his hand squeezes Brian’s tighter.

Mr. Kang’s eyes widen in fear, “Did you make it to your house Jae?”

Jae frowns and shakes his head, “No, I didn’t.”

“Do you want to go check?” Brian asks, Jae can hear fear in his voice.

“I can go with you two,” Mr. Kang offers.

“Please?” Jae begs.

The eldest man nods, then three of them begin to leave Brian’s house. This time, they take the shortest way there, running as they do so.

Jae stops in his tracks when he looks at his house. Tears threaten to spill as he sees half of his dad’s crushed body and sees a Titan ripping apart his mom. “No,” he whispers, tears running down his cheeks.

“Jae, I’m so sorry,” Brian says, pulling the other into a quick hug.

Jae doesn’t hug back, all he says is, “We need to get out of here.”

A few blocks away, they hear a man yell out, “Head toward the gate!”

Jae starts running that way, dragging Brian with him and Mr. Kang isn’t too far behind them. They enter the gate in minutes. “It looks like there’s boats up that way, people are boarding them!” Mr. Kang yells out.

“Hopefully we can make it before they leave,” the youngest of them say.

“We will,” Jae yells out.

They end up making it there in time while running past people. They quickly try getting onto one of the boats, sitting down once they are placed on one. “Which boat are we on?” Brian asks.

“Boat one, I believe,” Mr. Kang replies. After he says that, they can hear cannons start firing. Brian and Jae can hear more than just the cannons.

“What is that noise?” Brian asks as the boats begin to move.

“It sounds like running,” Jae answers, looking at the inner gate. Seconds later they hear yelling and then, a titan runs through the wall. “Holy shit,” Jae says, his eyes widening.

~

It’s been hours, they haven’t made it to wall Rose yet but they will soon. Jae is sitting on a bench, his knees brought up to his chest, his head resting on his knees. He’s staring out at the villages and trees that they pass by.

“Hey Brian?” Jae whispers, looking over at the younger.

“Yeah?” Brian replies, still looking out at the trees.

“I’ll join you and train to become a scout. We can go in tomorrow after we’ve gotten sleep,” Jae says.

Brian looks at the elder, his eyes wide. “Really? You really want to join?” he asks in disbelief.

“After today’s event,” images of his parents' bodies flash in his mind, he stops himself from crying, “yeah, I do.”

A smile forms on Brian’s face and he rests his head on Jae’s shoulder. They don’t say anything after this, the two of them just stay silent. Jae’s top reason as to why he wants to join is to keep the younger close to him. Brian and Mr. Kang are the only two people he has left and he wants to be able to protect them.

  
  


——

  
  


_ year: 850 (night before the battle of trost) _

_ ages: 17 and 18 _

  
  


Over the past five years, so much as happened for Jae and Brian. The two of them started training the day after wall Maria fell and they lost their homes. Both of them tried their hardest to be in the top ten. During their training time, they meet a guy named Sungjin. Those three became close immediately.

Sungjin told them that by the time they were graduating, his two best friends would start training, their names were Wonpil and Dowoon.

When they graduated, the three of them begged if they could go back and forth between helping the trainees and doing their duties. Because of this, Jae and Brian became a bit close with the younger two.

Unlike Jae and Brian, Sungjin didn’t join the Survey Corps, he ended up joining the Garrisons and had asked if he could stay in the Trost district so he can be closer to his friends.

Jae has surprised himself over the years, he thought he would have died in his first expedition, but the need to protect the younger male has made him come this far. He’s also very proud of how far Brian has come during all of this as well.

Currently, Jae and Brian are sitting in Commander Erwin’s office. It’s them, Erwin, and Levi. “You two are probably wondering why I called you in here so late,” Erwin says.

“Yes sir,” they say in unison.

“Well, Levi and I have been talking about you two, how you guys have only been doing this for two years but both of you are just as good as some of the veterans here. So, I was wanting to see if you wanted to join Levi’s squad during tomorrow’s expedition?” the commander asks, barely a smile on his face.

The youngest two’s eyes widen. “Really, you want us to join?” Jae asks in disbelief.

“Unless you don’t want to,” Levi says, looking at the two.

“No no, we would love to,” Brian replies, a wide smile on his face.

“Great! You two get some rest for tonight then,” Erwin says, the smile on his face growing.

The other two put their fist over their hearts, “Of course sir, thank you.” With that, the two leave Erwin’s office and head to their shared room.

“I can’t believe we are going to be in Levi’s squad,” Jae says as they enter their room.

“Yeah, me neither,” Brian says, chuckling softly.

“Hey, do you want to sit out on the roof ledge for a bit before we go to sleep?” Jae asks, pointing at the window.

Brian smiles softly, they haven’t done this in a while. “Yeah, sure,” he replies.

The two of them get dressed and then Jae opens up the window, they exit it and sit on the small roof. It stays silent between them for a good while, they are staring out at the town that they might have to call home for years. It feels like hours before one of them speaks, Brian ends up breaking the silence before Jae could.

“Hey Jae?” the younger whispers out, still looking at the town.

“Yeah?” Jae replies back, glancing at the other.

“I’ve been thinking and… when this is all over, whenever the hell that will be, let’s move into one of the villages between the walls? Just the two of us. We can find one that has a farm and by the forest! Doesn’t that sound lovely?” Brian is now looking at Jae, a grin plastered on his face.

Jae smiles back, “Yeah, it does. Though there’s one thing I want to do before we move in together.” His heartbeat picks up in pace.

“Oh, what is it?” Brian questions, tilting his head to the side.

The smile on Jae’s face grows more as he looks at the younger. “I want to marry you,” he says.

Pink begins to dust Brian’s cheeks as his eyes widen. “R-Really?” the younger stutters out.

“Well, of course I do. I wouldn’t want to spend the rest of my life with anyone else but you, Bri,” the elder replies.

The blush on Brian’s cheeks darken some. “Then… yeah, I would love that.”

“Promise then?”

“Promise.”

Jae doesn’t respond, he leans closer to the other male and places a kiss on his rosey cheeks. Brian smiles and moves closer to the elder, laying his head on his shoulder. Jae wraps his arm around Brian tightly.

_ I promise I’ll keep you safe, Bri. _

  
  


——

  
  


“Eh? What the hell?!”

The Survey Corps just came back from an expedition to see a  _ hole  _ in wall Rose. They are a good bit away from the wall so the titans haven’t seen them, which is good. Jae notices that the size of the hole is about the same size as the one in wall Maria.

“It was kicked down again,” Jae says as he looks at Brian.

“I can’t believe this happened on a day we weren’t in the wall,” Brian replies.

“Yeah…” Jae mutters.

“Alright, this is what we are going to do,” Levi starts as he turns around with his horse, “Jae, Brian, you’re going to the top of the wall with me. Everyone else, kill the titans by the hole. Are we clear?”

“Yes, sir!”

“Do you guys have enough gas to go up the wall?” Levi asks, looking at the two.

“We should, yeah,” Jae replies, nodding.

“Alright, let’s go,” the eldest of the three say.

The three of them ride their horses to a part of the wall away from the hole. When they get there, they get off of the horses and get their gear ready. They all grab their grappling hooks and shoot them up the wall.

“Let’s go,” Levi says and they press the button sending them up. Once on the way, Levi says, “I want you two to deal with the titans right there,” he points to his left, “and I'll deal with the ones over there.”

“Got it sir,” Brian replies. With that, Levi starts heading toward the right.

“How are we going to do this from up here. It’s too high to just jump and try to land on a roof,” Jae says, looking down over the wall.

“We can fall a bit and quickly shoot the grappling hooks at the wall and ease our way down,” Brian suggests.

“That’s actually not a bad idea.”

The two of them walk over to the edge and turn around to face where they came up from. “Do it on the count of three?” Brian asks, there’s a small smirk plastered on his face.

“Yeah, I’ll start. One..”

“Two..”

“Three!”

Both of them fall backwards and not too long after, they shoot out the two grappling hooks. “Holy shit, it worked!” the younger says happily.

Jae smiles and says, “Come on, let’s go down the wall.” They make it about where that half way point is before Jae groans out and curses. “Shit,” he mutters.

“What’s wrong?” Brian asks, concern obvious in his voice.

“I’m stuck here, they won’t move,” the elder replies as he frowns.

“Can you go back up?” the younger asks.

Jae tries to send himself back up but it doesn’t work. “Nope,” he sighs out.

It stays silent between the two. They end up wasting a bit of time while thinking about what they should do about the situation. Eventually, Brian speaks up and suggests, “Well, I can leave you here and take those two titans down myself?”

Jae’s eyes widen and he looks at the other. “Absolutely not. We can get me out of this and I can help you!”

“Jae, you wouldn’t be about to, your odm gear is messed up. I can handle the two titans myself, okay?” There’s a smile on the younger males face as he looks at Jae.

A huff escapes Jae’s lips and he says, “Fine.”

The smile on Brian’s face grows and he grabs a hold of Jae’s arm, pulling the elder closer to him. Jae gives him a look of confusion before the younger closes the distance between them. His eyes widen when he feels Brian’s lips on his own. Jae quickly recovers and kisses the younger back. Immediately after though, Brian pulls away.

“I’ll be back.” With that, the younger is off.

As Brian goes towards the titans, Jae tries to use the ropes of the grappling hooks to climb up the wall. He’s able to go up the wall some. Something inside him tells him that he  _ needs  _ to turn around and check on Brian. He twists his body around and his eyes fall on Brian.

Brian’s standing on top of a roof of one of the many houses, Jae notices that the two titans are lying on the floor, dead.

A proud smile forms on his face and he yells out, “Good job Bri!” With both of them being distracted, they don’t notice the titan heading toward Brian. Jae ends up noticing at the last second, “Brian! Watch o-”

As the younger turns around, he’s met with a titan hand coming right at him. Jae watches in horror as the titan grabs Brian, picking him up. The younger males arms are stuck inside the titans fist… he has no way of escaping. Jae starts to panic internally.

“Brian!” Jae yells out. Tears threaten to spill at the sound of Brian’s screams.

“N-No! Jae!”

Jae watches as the titan brings the younger up to its face, he watches as its mouth opens up wide, he watches as it bites Brian’s head off. Brian’s blood goes everywhere, making the elder cringe some, but not in disgust. His grip on the ropes ends up loosening, sending him back to the half point of the wall.

His eyes are still glued to the titan, it no longer has Brian in his hand. It either ate him or it dropped his body.

A scream passes Jae’s lips as his tears begin to fall. He quickly brings his hand up to his mouth, trying his best to muffle his scream and sobs. This ends up failing miserably.

It feels like hours before someone starts to pull at the grappling ropes, bringing his body up to the top of the wall. He still feels his body shaking from the shock, though he had stopped screaming and crying moments ago. He feels someone help him sit up and feels that person wrap their arm around his shoulder.

“Jae?” His breath gets caught in his throat as he turns his head to look at the person beside him. “Oh my… Jae? Are you okay?” Sungjin asks, his eyes filled with worry as he looks at the older male.

Jae can’t speak so he only nods his head and leans into the younger males touch.

Sungjin hesitates for a second before he asks, “Where’s Brian?” Their eyes meet again, Sungjin  _ can tell  _ what had happened by the way Jae’s eyes begin to fill with tears and his lip starts to quiver. “Oh Jae, I’m so sorry.” The younger pulls the other closer, hugging him properly. He tries not to cry himself.

They stay there for a few minutes so Jae can calm down. After sometime Jae whispers, “Can we head toward the other gate? I don’t want to be here anymore.” His eyes lands on the spot Brian was standing at not too long ago.

“Yeah, of course.” Sungjin helps Jae up and they begin to walk toward the other gate, though it’s a bit of a walk.

“How long has it been since the scouts have been back?” Jae asks, his voice soft.

“Over an hour, I’d say,” the younger replies.

“Oh. Has anything happened in the area where Captain Levi went?” Jae asks.

“Actually yeah, you won’t believe it either, but a titan started fighting alongside us. I’m pretty sure it still is,” he replies.

Jae’s eyes widen, “What?”

“Yeah, I know right? Pretty weird. He’s right over there,” Sungjin says and points. Jae follows his finger and sees the titan throwing another one out of his way.

“Oh, wow.”

It goes silent between the two as they start to near the gate. Jae ends up getting distracted by his mind, it begins to play everything that happened over and over again, causing him to frown. 

“Alright, we are here! Instead of staying here, would you want to go to the lower part of the gate and find somewhere to rest for a bit?”

“Yeah, sure,” Jae replies.

“Okay, let me notify some of the Garrison and scouts alright?”

“Okay,” Jae mutters.

Sungjin doesn’t leave him alone long, he’s back within minutes. “Let’s go!” he says, grabbing the elders hand.

~

A couple hours pass by, everyone ends up finding out the titan helping them out was actually Eren Yeager. With this information, it sent some people into a panic and others couldn’t care less. 

“Do you want to go watch Eren fix the wall?” Sungjin asks.

“No, not really,” Jae answers, staring at the floor.

“You want to stay here then?

“Yes.”

“Okay, that’s fine with me,” Sungjin rests his head on his hand, “I was thinking that I should switch to the scouts.”

Jae’s head snaps up and he looks at the younger male, “No you’re not, it’s too dangerous.”

Sungjin lets out a chuckle. “I don’t care, I’m doing this for you, the younger two, and… I know Brian would have been thrilled to know I was planning on joining.” The elder looks away from Sungjin as his eyes begin to tear up again. “Plus, I know for a fact you’ll end up doing something stupid that you’ll regret. I can’t watch you if I’m with the Garrisons.”

Jae sighs, “Okay…”

Sungjin smiles, “You’re not going to deal with his death by yourself, okay? Wonpil, Dowoon, and I will help you out and stick by your side.”

Jae’s eyes meet Sungjin’s, a small smile forms on his face. “Thank you for being here.”

“You don’t need to thank me, this is what friends are for.” Sungjin pulls Jae into a hug and hugs him tightly.

_ I’ll keep living for you, Bri. _


End file.
